Are you looking for mockups of specific plugins or more generalized mockups that look better than the average host generated UI?
Perhaps you could make an LV2 extension that marks certain control ports as "important" and then they would get included on such a host-generated, simplified UI. I dreamed a dream of doing this sort of thing for Rakarrack, since many users get overwhelmed by the dozen parameters on each effect. It would be nice to have a "simple mode" with the 2-4 most important parameters. Perhaps the ttl could even indicate some background, knob, and logo images to allow the plugin developers to customize the look. Just some thoughts.
